/*=========================================================================*\
* Unix domain socket stream sub module
* LuaSocket toolkit
\*=========================================================================*/
#include <string.h>

#include "lua.h"
#include "lauxlib.h"
#include "compat.h"

#include "auxiliar.h"
#include "socket.h"
#include "options.h"
#include "unixstream.h"
#include <sys/un.h>

/*=========================================================================*\
* Internal function prototypes
\*=========================================================================*/
static int global_create(lua_State* L);
static int meth_connect(lua_State* L);
static int meth_listen(lua_State* L);
static int meth_bind(lua_State* L);
static int meth_send(lua_State* L);
static int meth_shutdown(lua_State* L);
static int meth_receive(lua_State* L);
static int meth_accept(lua_State* L);
static int meth_close(lua_State* L);
static int meth_setoption(lua_State* L);
static int meth_settimeout(lua_State* L);
static int meth_getfd(lua_State* L);
static int meth_setfd(lua_State* L);
static int meth_dirty(lua_State* L);
static int meth_getstats(lua_State* L);
static int meth_setstats(lua_State* L);
static int meth_getsockname(lua_State* L);

static const char* unixstream_tryconnect(p_unix un, const char* path);
static const char* unixstream_trybind(p_unix un, const char* path);

/* unixstream object methods */
static luaL_Reg unixstream_methods[] = {
    {"__gc", meth_close},
    {"__tostring", auxiliar_tostring},
    {"accept", meth_accept},
    {"bind", meth_bind},
    {"close", meth_close},
    {"connect", meth_connect},
    {"dirty", meth_dirty},
    {"getfd", meth_getfd},
    {"getstats", meth_getstats},
    {"setstats", meth_setstats},
    {"listen", meth_listen},
    {"receive", meth_receive},
    {"send", meth_send},
    {"setfd", meth_setfd},
    {"setoption", meth_setoption},
    {"setpeername", meth_connect},
    {"setsockname", meth_bind},
    {"getsockname", meth_getsockname},
    {"settimeout", meth_settimeout},
    {"shutdown", meth_shutdown},
    {NULL, NULL},
};

/* socket option handlers */
static t_opt optset[] = {
    {"keepalive", opt_set_keepalive},
    {"reuseaddr", opt_set_reuseaddr},
    {"linger", opt_set_linger},
    {NULL, NULL},
};

/* functions in library namespace */
static luaL_Reg func[] = {
    {"stream", global_create},
    {NULL, NULL},
};

/*-------------------------------------------------------------------------*\
* Initializes module
\*-------------------------------------------------------------------------*/
int unixstream_open(lua_State* L) {
  /* create classes */
  auxiliar_newclass(L, "unixstream{master}", unixstream_methods);
  auxiliar_newclass(L, "unixstream{client}", unixstream_methods);
  auxiliar_newclass(L, "unixstream{server}", unixstream_methods);

  /* create class groups */
  auxiliar_add2group(L, "unixstream{master}", "unixstream{any}");
  auxiliar_add2group(L, "unixstream{client}", "unixstream{any}");
  auxiliar_add2group(L, "unixstream{server}", "unixstream{any}");

  luaL_setfuncs(L, func, 0);
  return 0;
}

/*=========================================================================*\
* Lua methods
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Just call buffered IO methods
\*-------------------------------------------------------------------------*/
static int meth_send(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{client}", 1);
  return buffer_meth_send(L, &un->buf);
}

static int meth_receive(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{client}", 1);
  return buffer_meth_receive(L, &un->buf);
}

static int meth_getstats(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{client}", 1);
  return buffer_meth_getstats(L, &un->buf);
}

static int meth_setstats(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{client}", 1);
  return buffer_meth_setstats(L, &un->buf);
}

/*-------------------------------------------------------------------------*\
* Just call option handler
\*-------------------------------------------------------------------------*/
static int meth_setoption(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  return opt_meth_setoption(L, optset, &un->sock);
}

/*-------------------------------------------------------------------------*\
* Select support methods
\*-------------------------------------------------------------------------*/
static int meth_getfd(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  lua_pushnumber(L, (int)un->sock);
  return 1;
}

/* this is very dangerous, but can be handy for those that are brave enough */
static int meth_setfd(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  un->sock = (t_socket)luaL_checknumber(L, 2);
  return 0;
}

static int meth_dirty(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  lua_pushboolean(L, !buffer_isempty(&un->buf));
  return 1;
}

/*-------------------------------------------------------------------------*\
* Waits for and returns a client object attempting connection to the
* server object
\*-------------------------------------------------------------------------*/
static int meth_accept(lua_State* L) {
  p_unix server = (p_unix)auxiliar_checkclass(L, "unixstream{server}", 1);
  p_timeout tm = timeout_markstart(&server->tm);
  t_socket sock;
  int err = socket_accept(&server->sock, &sock, NULL, NULL, tm);
  /* if successful, push client socket */
  if (err == IO_DONE) {
    p_unix clnt = (p_unix)lua_newuserdata(L, sizeof(t_unix));
    auxiliar_setclass(L, "unixstream{client}", -1);
    /* initialize structure fields */
    socket_setnonblocking(&sock);
    clnt->sock = sock;
    io_init(&clnt->io, (p_send)socket_send, (p_recv)socket_recv, (p_error)socket_ioerror, &clnt->sock);
    timeout_init(&clnt->tm, -1, -1);
    buffer_init(&clnt->buf, &clnt->io, &clnt->tm);
    return 1;
  } else {
    lua_pushnil(L);
    lua_pushstring(L, socket_strerror(err));
    return 2;
  }
}

/*-------------------------------------------------------------------------*\
* Binds an object to an address
\*-------------------------------------------------------------------------*/
static const char* unixstream_trybind(p_unix un, const char* path) {
  struct sockaddr_un local;
  size_t len = strlen(path);
  int err;
  if (len >= sizeof(local.sun_path))
    return "path too long";
  memset(&local, 0, sizeof(local));
  strcpy(local.sun_path, path);
  local.sun_family = AF_UNIX;
#ifdef UNIX_HAS_SUN_LEN
  local.sun_len = sizeof(local.sun_family) + sizeof(local.sun_len) + len + 1;
  err = socket_bind(&un->sock, (SA*)&local, local.sun_len);

#else
  err = socket_bind(&un->sock, (SA*)&local, (socklen_t)(sizeof(local.sun_family) + len));
#endif
  if (err != IO_DONE)
    socket_destroy(&un->sock);
  return socket_strerror(err);
}

static int meth_bind(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{master}", 1);
  const char* path = luaL_checkstring(L, 2);
  const char* err = unixstream_trybind(un, path);
  if (err) {
    lua_pushnil(L);
    lua_pushstring(L, err);
    return 2;
  }
  lua_pushnumber(L, 1);
  return 1;
}

static int meth_getsockname(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  struct sockaddr_un peer = {0};
  socklen_t peer_len = sizeof(peer);

  if (getsockname(un->sock, (SA*)&peer, &peer_len) < 0) {
    lua_pushnil(L);
    lua_pushstring(L, socket_strerror(errno));
    return 2;
  }

  lua_pushstring(L, peer.sun_path);
  return 1;
}

/*-------------------------------------------------------------------------*\
* Turns a master unixstream object into a client object.
\*-------------------------------------------------------------------------*/
static const char* unixstream_tryconnect(p_unix un, const char* path) {
  struct sockaddr_un remote;
  int err;
  size_t len = strlen(path);
  if (len >= sizeof(remote.sun_path))
    return "path too long";
  memset(&remote, 0, sizeof(remote));
  strcpy(remote.sun_path, path);
  remote.sun_family = AF_UNIX;
  timeout_markstart(&un->tm);
#ifdef UNIX_HAS_SUN_LEN
  remote.sun_len = sizeof(remote.sun_family) + sizeof(remote.sun_len) + len + 1;
  err = socket_connect(&un->sock, (SA*)&remote, remote.sun_len, &un->tm);
#else
  err = socket_connect(&un->sock, (SA*)&remote, (socklen_t)(sizeof(remote.sun_family) + len), &un->tm);
#endif
  if (err != IO_DONE)
    socket_destroy(&un->sock);
  return socket_strerror(err);
}

static int meth_connect(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{master}", 1);
  const char* path = luaL_checkstring(L, 2);
  const char* err = unixstream_tryconnect(un, path);
  if (err) {
    lua_pushnil(L);
    lua_pushstring(L, err);
    return 2;
  }
  /* turn master object into a client object */
  auxiliar_setclass(L, "unixstream{client}", 1);
  lua_pushnumber(L, 1);
  return 1;
}

/*-------------------------------------------------------------------------*\
* Closes socket used by object
\*-------------------------------------------------------------------------*/
static int meth_close(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  socket_destroy(&un->sock);
  lua_pushnumber(L, 1);
  return 1;
}

/*-------------------------------------------------------------------------*\
* Puts the sockt in listen mode
\*-------------------------------------------------------------------------*/
static int meth_listen(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkclass(L, "unixstream{master}", 1);
  int backlog = (int)luaL_optnumber(L, 2, 32);
  int err = socket_listen(&un->sock, backlog);
  if (err != IO_DONE) {
    lua_pushnil(L);
    lua_pushstring(L, socket_strerror(err));
    return 2;
  }
  /* turn master object into a server object */
  auxiliar_setclass(L, "unixstream{server}", 1);
  lua_pushnumber(L, 1);
  return 1;
}

/*-------------------------------------------------------------------------*\
* Shuts the connection down partially
\*-------------------------------------------------------------------------*/
static int meth_shutdown(lua_State* L) {
  /* SHUT_RD,  SHUT_WR,  SHUT_RDWR  have  the value 0, 1, 2, so we can use method index directly */
  static const char* methods[] = {"receive", "send", "both", NULL};
  p_unix stream = (p_unix)auxiliar_checkclass(L, "unixstream{client}", 1);
  int how = luaL_checkoption(L, 2, "both", methods);
  socket_shutdown(&stream->sock, how);
  lua_pushnumber(L, 1);
  return 1;
}

/*-------------------------------------------------------------------------*\
* Just call tm methods
\*-------------------------------------------------------------------------*/
static int meth_settimeout(lua_State* L) {
  p_unix un = (p_unix)auxiliar_checkgroup(L, "unixstream{any}", 1);
  return timeout_meth_settimeout(L, &un->tm);
}

/*=========================================================================*\
* Library functions
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Creates a master unixstream object
\*-------------------------------------------------------------------------*/
static int global_create(lua_State* L) {
  t_socket sock;
  int err = socket_create(&sock, AF_UNIX, SOCK_STREAM, 0);
  /* try to allocate a system socket */
  if (err == IO_DONE) {
    /* allocate unixstream object */
    p_unix un = (p_unix)lua_newuserdata(L, sizeof(t_unix));
    /* set its type as master object */
    auxiliar_setclass(L, "unixstream{master}", -1);
    /* initialize remaining structure fields */
    socket_setnonblocking(&sock);
    un->sock = sock;
    io_init(&un->io, (p_send)socket_send, (p_recv)socket_recv, (p_error)socket_ioerror, &un->sock);
    timeout_init(&un->tm, -1, -1);
    buffer_init(&un->buf, &un->io, &un->tm);
    return 1;
  } else {
    lua_pushnil(L);
    lua_pushstring(L, socket_strerror(err));
    return 2;
  }
}
